Diphtheria is a bacterial infection that spreads easily and occurs quickly. It mainly affects the nose and throat. Children under 5 and adults over 60 years old are particularly at risk for contracting the infection. People living in crowded or unclean conditions, those who aren't well nourished, and children and adults who don't have up-to-date immunizations are also at risk.

Diphtheria is rare in the United States and Europe, where health officials have been immunizing children against it for decades. However, it's still common in developing countries where immunizations aren't given routinely. In 1993 and 1994, more than 50,000 cases were reported during a serious outbreak of diphtheria in countries of the former Soviet Union.

Signs and Symptoms

In its early stages, diphtheria can be mistaken for a bad sore throat. A low-grade fever and swollen neck glands are the other early symptoms.

The toxin, or poison, caused by the bacteria can lead to a thick coating in the nose, throat, or airway. This coating is usually fuzzy gray or black and can cause breathing problems and difficulty in swallowing. The formation of this coating (or membrane) in the nose, throat, or airway makes a diphtheria infection different from other more common infections (such as strep throat) that cause sore throat.

As the infection progresses, the person may:

have difficulty breathing or swallowing

complain of double vision

have slurred speech

even show signs of going into shock (skin that's pale and cold, rapid heartbeat, sweating, and an anxious appearance)

In cases that progress beyond a throat infection, diphtheria toxin spreads through the bloodstream and can lead to potentially life-threatening complications that affect other organs of the body, such as the heart and kidneys. The toxin can cause damage to the heart that affects its ability to pump blood or the kidneys' ability to clear wastes. It can also cause nerve damage, eventually leading to paralysis. Up to 40% to 50% of those who don't get treated can die.

Prevention

Preventing diphtheria depends almost completely on immunizing children with the diphtheria/tetanus/pertussis (DTP or DTaP) vaccine and non-immunized adults with the diphtheria/tetanus vaccine (DT). Most cases of diphtheria occur in people who haven't received the vaccine at all or haven't received the entire course.

The immunization schedule calls for:

DTaP vaccines at 2, 4, and 6 months of age

booster dose given at 12 to 18 months

booster dose given again at 4 to 6 years

booster shots given every 10 years after that to maintain protection

Although most children tolerate it well, the vaccine sometimes causes mild side effects such as redness or tenderness at the injection site, a low-grade fever, or general fussiness or crankiness. Severe complications, such as an allergic reaction, are rare.

Contagiousness

Diphtheria is highly contagious. It's easily passed from the infected person to others through sneezing, coughing, or even laughing. It can also be spread to others who pick up tissues or drinking glasses that have been used by the infected person.

People who have been infected by the diphtheria bacteria can infect others for up to 4 weeks, even if they don't have any symptoms. The incubation period (the time it takes for a person to become infected after being exposed) for diphtheria is 2 to 4 days, although it can range from 1 to 6 days.

Treatment

Children and adults with diphtheria are treated in a hospital. After a doctor confirms the diagnosis through a throat culture, the infected person receives a special anti-toxin, given through injections or through an IV, to neutralize the diphtheria toxin already circulating in the body, as well as antibiotics to kill the remaining diphtheria bacteria.

If the infection is advanced, people with diphtheria may need a ventilator to help them breathe. In cases in which the toxins may have spread to the heart, kidneys, or central nervous system, patients may need intravenous fluids, oxygen, or heart medications.

A person with diphtheria must also be isolated. Family members (as well as others who spend a lot of time with the person with diphtheria) who haven't been immunized, or who are very young or elderly, must be protected from contact with the patient.

When someone is diagnosed with diphtheria, the doctor will notify the local health department and will take steps to treat everyone in the household who may have been exposed to the bacteria. This will include assessment of immune status, throat cultures, and booster doses of the diphtheria vaccine. They will also receive antibiotics as a precaution.

Immediate hospitalization and early intervention allow most patients to recover from diphtheria. After the antibiotics and anti-toxin have taken effect, someone with diphtheria will need bed rest for a while (4 to 6 weeks, or until full recovery). Bed rest is particularly important if the person's heart has been affected by the disease. Myocarditis, or inflammation of the heart muscle, can be a complication of diphtheria.

Those who have recovered should still receive a full course of the diphtheria vaccine to prevent a recurrence because contracting the disease doesn't guarantee lifetime immunity.

When to Call the Doctor

Call your doctor immediately if you or your child has symptoms of diphtheria, if you observe symptoms in someone else, if anyone in your family is exposed to diphtheria, or if you think that you or a family member is at risk. It's important to remember, though, that most throat infections are not diphtheria, especially in countries that have routine immunizations against it.

If you're not sure if your child has been vaccinated against diphtheria, make an appointment. Also make sure your own booster immunizations are current. International studies have shown that a significant percentage of adults over 40 years of age aren't adequately protected against diphtheria and tetanus.